1. Field of the Invention
The present invention relates to an electrode clamp device for use in electrochemical machines for simultaneously holding a plurality of tubular metallic electrodes.
2. Related Art Statement
There has been used an electrochemical machine for forming apertures in a die of a ceramic extruder. Such an electrochemical machine includes an electrode clamp device adapted for simultaneously holding a plurality of tubular metallic electrodes which are used for forming a number of fine apertures in the die, the while an electrolyte such as nitric acid is blown to the die through the tubular metallic electrodes.
A conventional clamp device which has been used in such an electrochemical machining comprises two split clamp blocks 21-1 and 21-2 which are separated along a zigzag split line to provide concave portions 22-1 and convex portions 22-2. The concave portions 22-1 and the convex portions 22-2 are provided with recesses 23-1 and 23-2 at apexes of the zigzag split line for holding tubular metallic electrodes 24. The tubular metallic electrodes 24 are arranged in the recesses 23-1 and 23-2, and the clamp blocks 21-1 and 21-2 are matched together to hold the tubular metallic electrodes. Then the clamp blocks are fastened by means of screws 25 to simultaneously clamp the electrodes.
The conventional clamp device as mentioned above holds together all of the tubular metallic electrodes by two clamp blocks fastened together by means of screws.
Therefore, problems arise in that some of the tubular metallic electrodes clamped between the clamp blocks can be displaced in or detached from the clamp blocks or collapses between because of variability of diameter of the tubular metallic electrodes and accuracy of finishing of the concave and convex portions and the recesses, and as the result the electrochemical machining can not be satisfactorily performed, resulting in tubular metallic electrodes that can not be used again.
Furthermore, it is difficult to accurately finish the recess to a determined radius of curvature such that the corresponding tubular metallic electrode is satisfactorily fitted in the recess in order to be firmly gripped by the clamp blocks.